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Updated: May 26, 2026
12:22
Speciation and Bioavailability Measurements of Environmental Plutonium Using Diffusion in Thin Films
Published on: November 9, 2015
Determination of 239Pu/240Pu isotopic ratio by high-resolution alpha-particle spectrometry using the ADAM program
R Pöllänen1, T Siiskonen, S Ihantola
1STUK-Radiation and Nuclear Safety Authority, PO Box 14, FI-00881 Helsinki, Finland. roy.pollanen@stuk.fi
Summary
A new software, ADAM, accurately analyzes alpha spectra for plutonium isotopes (239Pu and 240Pu). This validated method ensures reliable activity ratio measurements crucial for nuclear science applications.
Area of Science:
- Nuclear Chemistry
- Spectroscopy
- Analytical Chemistry
Background:
- Accurate quantification of plutonium isotopes is essential for nuclear safeguards and environmental monitoring.
- Traditional methods for analyzing alpha spectra can be limited by peak overlap and complex decay characteristics.
Purpose of the Study:
- To introduce and validate a novel software program, ADAM, for unfolding alpha-particle energy spectra.
- To assess the accuracy of ADAM in determining (239)Pu/(240)Pu activity ratios using radiochemically processed sources.
Main Methods:
- Utilized a high-resolution alpha spectrometer for data acquisition.
- Employed the ADAM software, which constrains spectral unfolding with nuclide-specific decay data.
- Accounted for various peak shapes and coincidences between alpha particles and electrons/photons.
Main Results:
- The (239)Pu/(240)Pu activity ratios determined by alpha spectrometry using ADAM agreed with reference values within uncertainties.
- Reliable results require a minimum of 100 counts in the (239,240)Pu peak group for semiconductor detectors with 10.6 keV FWHM resolution.
Conclusions:
- The ADAM software provides a validated and accurate method for unfolding alpha spectra.
- ADAM's ability to handle complex spectral features enhances the reliability of plutonium isotope analysis.
- The study establishes a minimum count threshold for obtaining dependable results in plutonium isotopic analysis.
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